The gradual shift in ocean temperature was unnoticeable to swimmers but significant for coral reef ecosystems.
海洋温度的逐渐变化对游泳者来说不显眼，但对珊瑚礁生态系统却意义重大。
Which choice best defines “unnoticeable”?
B — Not easily seen or noticed. “unnoticeable” means not easily seen or noticed.
Which word means “not easily seen or noticed”?
A — unnoticeable. “unnoticeable” means not easily seen or noticed.
unnoticeable — not easily seen or noticed. In Chinese: 不显眼的.
unnoticeable is pronounced /ʌnˈnoʊtɪsəbl/.
The gradual shift in ocean temperature was unnoticeable to swimmers but significant for coral reef ecosystems. (海洋温度的逐渐变化对游泳者来说不显眼，但对珊瑚礁生态系统却意义重大。)
imperceptible, inconspicuous, subtle — all close in meaning to unnoticeable (not easily seen or noticed).
noticeable, conspicuous — each the opposite of unnoticeable (not easily seen or noticed).
Yes. unnoticeable is on the SAT Prep Basic list — the everyday academic words the SAT assumes you already have. The Digital SAT does not test vocabulary in isolation; words like this one are tested through Words in Context questions, where you choose the word that completes a passage most logically and precisely.